Piston packing



Oct 2, 1928.

J. w. M CLATCHlE PISTON PACKING Filed Dec. 22, 1926 INVENTOR. JOHN W. MAC CLA TCH/E A TTORNEY.

Patented Oct. 2, 1928.

UNITED STATES 1,686,090 PATENT OFFICE.

JOHN W; 'MAGCLATCHIE, OI COMPTON, CALIFORNIA.

PISTON rncxme.

. Application filed December 22, 1926. Serial No. 156,284.

- one another and thereby axially compress the interp osed packing and cause its radial ex pension. I a

is a still furtherobject of the invention to limit movement of the slidable abutment members away from one another so as tomaintain the parts in assembled relation; and

v the improved construction also provides for convement replacement of the packing and the abutment members when they become worn, while continuing to use the same main portion of the piston which is not subject to:

28 wearing action,thereby providing for quick and inexpensive renewal of the piston.

g It is a still further object of the invention to arrange the parts so that, maximum radial expansion will occur at the endsof the pack- 8 ing annulus, thereby insuring a tight packing engagement an wiping the wall of the cylinder free of foreign matter without the? possibilityof'such "foreign matter seatingbetween the packing and. the cylinder wall and; wri scoring-the'latter. J i v Furtherobjectsof the invention willbe. flunderstood from the following description of the'accompanying drawings, in whicht' Fig. 2 is an end view of the same. w

The improved packing is mounted on a piston 1 which reciprocates in any usual cylinder 2, the piston being reciprocated by a a usual piston rod 3 having a tapering end 4 terminating in a threaded pin 5, and received in a usual tapering bore 6 extending through the piston.

A cylindrical peripheral surface 7 forms a seat for the packing and extends to one end of piston, and the opposite end of the piston forms an annular flange 8 projecting radially beyond surface 7 for an appreciable distance but of a diameter considerably less than that 55 of cylinder 2. A disc 9 of the same diameter as flange 8 is slidably received on threaded in 5 against the other end of peripheral surace 7, and is removably held in place by a nut 10 threaded on pin 5, the members 8 and 9 thus forming radially projecting abut- .ments at the respective ends of surface 7,

with said abutments spaced a considerable distance from the wall of cylinder 2.

Sleeves 12 of non-distortable material such as a suitable metal are slidably mounted on members 89 and are slidable in cylinder 2 Without binding engagement, the outer ends.

of the sleeves forming annular abutment surfaces 13 of appreciable width in planes at right angles to the axis of the piston and subject to the pressure in cylinder 2 so as to tend to slide the sleeves toward one another. The inner ends of the sleeves form interior annular flanges. 14 extending inwardly to the peripheral surface 7 and .slidable thereon,

' with the outer surfaces of the interior flanges adaptedfor abutment against members 8-9 to limit movement of sleeves 12 away from one another. l

A packing annulus 16 which maybe of any.

usual packing material, is mounted on pcripheral surface 7 between the sleeves 12, and

is of a diameter adapted for packing engagement with the wall of cylinder 2 when the packing annulus is axially compressed. The

ends of the packing annulus and the inner surfaces of the interior flanges of sleeve 12,. form co-operating abutment faces 17 so that the pressure in cylinder 2 sliding the sleeves 12 toward one another will axially compress packing 16 for radial expansion into packing engagement with the wall of cylinder 2.

The co-operating abutment surfaces 17 at I 1therespect1ve ends of the packing annulus- Fig. 1 is a side elevation of theimproved" (a construction, artly in axial section; "1': Ina-5' preferably convergently taper toward the BXIS'QftllGPlStOII as shown in Fig. 1, so that the immediate ends of its peripheral sur as shown at 20.

To further. insure maximum packing engagement at theends 20, the medial portion of the packing annulus may be weakened, as for example by means of an annular recess 21 portion 0 the packing annulus is of reduced thickness as compared with the relatively greater uniform thickness of the end portions .ofthe annulus, this construction resulting in in its peri heral surface whereby the medial 1 greater radial expansion of the packing at its ends than at its medial portion, and thereby c linder 2, so that such pressure will positively force the sleeves toward one another and thereby automatically take up wear and maintain a tight packing engagement by annulus'16.

The sleeves 1 2 fit comparatively snuglym linder 2, so that the pressure in the cylind er is directed against the sleeves which are preferably of metal, and is not directed mmediately a ainst the ackin annulus which is of usua relative y yiel dable material. Maximum packing engagement is thus obtained with minimum wear.

The arrangement also provides for the nec-' essary radial expansion of packin 16 by relatively slight axial compression, it being noted that the required sliding movement of sleeves 12 toward one another is comparatively slight as shown in Fi 1, although if the packing annulus is bad y worn, the sleeves 12 are adapted for the necessary sliding movement to .take up appreciable wear.

Iclaini: i 1. A iston adapted for reciprocation in a cylin er containing a medium under pressure, a packing annulus on the piston, and an abutment slidable relative to the piston re-.

- sponsive to the pressure in the cylinder and en gin the end of the packing for axially coi n pres ing the packing and thereby radially expanding it into packin engagement wit the wall of the cylinder, the packing annulus being recessed medially of its length to reduce its thickness and havingjnd portions of uniform relatively greater t 'cknes extending from said medial recess to the respective ends of the annulus.

2. A member adapted for movement in an inclosure containing a medium under press sleeves slidable on the respective ends of t -membe r res nsive to the pressure in the. inclosure beyon the respective ends of the member, and a packing annulus on the member between the sleeves adapted for end engagement by the sliding sleeves to axially compress the packing annulus and thereby radially e and it into engagement with the wall of the inclosure, the packing annulus beingrecessed medially of its length to reduce its thickness and having end rtions of uni form relatively greater thi ess extendi from said medial remss to the respective en of the annulus.

3. A piston having radially projecting sure apackin aseepeo abutments at its respective ends, sleeves of non-distortable material slidable on said abutments and having interior flanges at their inner ends engaging said abutments for limiting-sliding movement of said sleeves away from one another, and a packing annulus on the piston between the sleeves adapted for end engagement by said interior flan es to axially com ress the packi movement 0 the sleeves towar one another and thereby radially expand the packing beyond the exterior iphery ofthe sleeves, the

acking annulus ing recessed medially of its length to reduce its thickness and having end portions of uniform. relatively greater thickness extending from said medial recess to the respective ends of the annulus.

4. A member adapted for movement in an inclosure containing a medium under presannulus on said member, and an a utment idable relative to the member responsive to the ressiire in the inclosure and engaging the emfof the packin for axially .compressinthe packing and t ereby radially expan ing it into packing engagement with the wall of the inc osure, the outer periph of the packin annulus being recessed media ly of its lengt to reduce its thickness with the end portions of said outer peri hery of the annulus of appreciable length an substantially parallel to the axis ofthe movable member.

5. A member adapted for movement in an inclosure containing a medium under ressure, sleeves slidable on the respective en s of the member responsive-to the pressure in the inclosure beyond the respective ends of the member, an a packing annulus on the member between the sleeves ada ted for end engagement by the sliding s eeves to axially compress the packing annulus and thereby radiall expand it into engagement with the wall 0 the inclosure, the outer periphery of the packingqannulus being recessed medially of its lengt to reduce its thickness with the end rtions of said outer periphery of the ann us of appreciable length and substan: tially parallel to the axis of member. I I a 6. A piston having radiall projectin abutments at its respective en 5, sleeves o non-distortable material slidable on said abutments and having their inner ends engaging said abutments for limiting sliding movement of said sleeves away from one another, and a acking annulus on the piston between the s eeves adapted for end engagement by said interior flanges interior flanges at lit) ' iii:

to axially compress the packing by sliding movement of the sleeves toward oneanother and thereby radially expand the packing beof the sleeves, the

iau

ripliery 0f the annulus of appreciable Tn and substantially parallel to the axis sift the piston.

31 A pneking annulus adapted for axial annex" periphery of the packing annulus being reeessei medially of its length to reduce its eumpressinn to radially expand the same,- the,

thickness with the end portions of said outer periphery of the annulus of appreciable lenith and substantially parallel to the bore 10 0ft e annulus.

In testimony whereof he has aflixed his signature to this specification.

JOHN W. MAGCLATCHIE. 

